Heart Valve Tissue Engineering

Abstract

Abstract-Tissue-engineered heart valves have been proposed by physicians and scientists alike to be the ultimate solution for treating valvular heart disease. Rather than replacing a diseased or defective native valve with a mechanical or animal tissue-derived artificial valve, a tissue-engineered valve would be a living organ, able to respond to growth and physiological forces in the same way that the native aortic valve does. Two main approaches have been attempted over the past 10 to 15 years: regeneration and repopulation. Regeneration involves the implantation of a resorbable matrix that is expected to remodel in vivo and yield a functional valve composed of the cells and connective tissue proteins of the patient. Repopulation involves implanting a whole porcine aortic valve that has been previously cleaned of all pig cells, leaving an intact, mechanically sound connective tissue matrix. The cells of the patients are expected to repopulate and revitalize the acellular matrix, creating living tissue that already has the complex microstructure necessary for proper function and durability. Regrettably, neither of the 2 approaches has fared well in animal experiments, and the only clinical experience with tissue-engineered valves resulted in a number of early failures and patient death. This article reviews the technological details of the 2 main approaches, their rationale, their strengths and weaknesses, and the likely mechanisms for their failure. Alternative approaches to valvular tissue engineering, as well as the role of industry in shaping this field in the future, are also reviewed.

Effects of decellularization on the mechanical and structural properties of the porcine aortic valve leaflet

“…While heart valve tissue engineering has generated much interest, many unanswered questions remain and technical barriers must be overcome before widespread clinical application can be envisioned [41][42][43]. Normal heart valves are vital and dynamic tissues composed of specialized cells and ECM that respond and remodel in response to changes in local mechanical forces [42].…”

Degradable PHBHHx Modified by the Silk Fibroin for the Applications of Cardiovascular Tissue Engineering

“…where γ 1 The optical density value of the hSMCs on the SF-modified PHBHHx scaffold with PHBHHx scaffold as control. n = 3, * P < 0.01, * * P > 0.05 [25].…”

“…The heart valve and blood vessel are composed by three important cells, fibroblasts, smooth muscle cells, and endothelial cells (ECs) as well [1] and [19,25,28]. The biocompatibility of human fibroblasts, human smooth muscle cells (hSMCs), and human umbilical vein endothelial cells (HUVECs) on the PHBHHx and SF-modified PHBHHx scaffolds were investigated.…”

“…In the field of cardiovascular disease, more than 100,000 patients in USA every year need to have their dysfunctional or diseased valves replaced with the prosthetic valves [1]. The traditional artificial heart valves are made from inert metals or nondegradable polymers to maintain the basic physiological functions.…”

Decisão mecânica ou biológica?

“…The international demand for valvar prostheses causes a growing economical and financial implication; the market in the United States of America estimated a worldwide profit of more than one billion dollars in 2005 10 .…”